Incandescent lamp.



L. GLASER.

, INGANDESGBNT LAMP.

APPLICATION FILED MAB. 3, 1908.

1,023,307. Patented Apr. 16, 1912.

2 SHEETS-SHEET 1.

Witnesses: Inventor:

muy.

Ludw Glaser, @Zh/iai" ...M/Aa.;

L. GLASER.

INCANDESGENT LAMP.

APPLIOATION IILED MAB. a. 1908.

1 ,023,307. Patented Apr. 16, 1912.

2 SHEETS-SHEET Z.

Witnesses: Inventor:

,y Ludwig Glaser,

@MJZ A UNITED STATE/s, IaTENlV OFFICE.

LUDWIG GLAsER,' or PANKOW, GERMANYQAssIGNoR To GENERAL ELECTRIC CoM- PANY, A CORPORATION. orv NEW YORK.

INCANDESCENT LAMP.

`Specification. of Letters Patent.

. Patented Apr. 16, 1912.

Application mea March a, 190s. serial No. 418,960.

To all 'whom it may concern.'

Be it known that I, .LUDWIG GLASER, a subject of the Grand Duke of Saxe-Coburg- Gotha, residing at Pankow, Germany, have invented certain newand useful Improvements in Incandescent Lamps, of which the following is a specification.

Filaments of incandescent lamps should` be anchored or fastenedfor the following reasons: first, in'order to avoid breakage of the laments during transportation, and second, in order to avoid vContact of the softened filaments, when glowing, either with themselves or with the glass pedestal of the lamp. Various fixed anchoring devices of a variety of materials have been used, but all of them have the disadvantage that the filatage is entirely obviated' when the anchoringl device is constructed of two parts, one part being united firmly on aninner rod or upon the walls of the bulb, while the second part is movable in such a manner that it will prevent lateral movement of the filament but will allow free linear expansion and contrac-l tion. The weight alone of the secondjpart of the anchoring device enters into effect,

and this vmay be made as small as possible in proportion to th'ediameter of the fila-` ments, so'that no mechanical destructlon of the filament willresult therefrom. l.

For a better understanding ofmy invenvtion reference may be had to the accompanying drawings in which-e Figure 1 is an elevation of a lamp having my improved filament support; F1g. 2 1s an enlarged detail of the supports;'Fig. 3 is a plan of the same; Fig. 4 is a sectional elevation through the lamp stem; Flg. 5 1s a modification thereof; Figs. 6 to 8 inclusive. show a second modification Figs. 9 to 11 inclusive show. still another embodiment of my in 7 passes through two loops 8a.

In` the transportation of lamps it is unavoidablefthat they take a position different vent-ion; 12 is a detail view of a modified form of support, and Fig. 13 shows 'a support consisting of wires of different sizes fused together.

The stirrup shaped filaments 1 are supported from the usual current supply wires 2 and are grouped about a vcentral glass pedestal 3. Each filament engages at its lower end with a guiding loop 4 of the anchoring device having its opposite end 5 wound in spiral manner about a hook 6 in the end of the glass pedestal. The guiding loop 4 is thus free to move up and down by turning on hook 6 as a pivot. If it happens that the filaments l are ofl such nature that they will still contract several millimeters while in the lamp, as by sintering together, it is advantageous to arrange the movable anchoring parts -when the lamp is sealed in a position extending away from the socket of the lamp, as shown inv Figs. 1 and 2, in order that when the filaments are entirely sintered together the anchors will draw up horizontally in the lamp to a degree that maybe considerable if these parts are of considerable length. By so doing, the anchoring device extends the filaments somewhat farther toward the sides of the bulb, so that a more favorable end-on lighting effect is obtained. This special advantage is lacking in the modification shown in Fig. 5 which, however, is distinguished by greater simplicity. In this arrangement the guiding loops or hooks 7 hang on the filaments and have stems or projections passed downward vthrough a loop 8 formed by the fixed'part. Instead of a single guiding loop two may be arranged, oneabove the other,

as illu'stratedby Fig. 12, in which the hook from that in which the filaments hang freely from above. It therefore may easily occur v that .because of a shock, holders'willv revolve 180 degrees and thereby the filaments may be destroyed, or because .of this revolution a short .circuit may occur when later the currentis turned on. To avoid the possibility lof. trouble from this cause, I may arrange trated in Figs. 6 to 8 inclusive, in which the the hook-like fixed part 10, and end in stops 11l which when revolving touch the radial parts of the hooks.

As already stated, the metal filaments may shrink considerably during the first few hours of glowin in the lamp.y A s it is not easily arrange that all filaments will shorten to the same degree, it is to be feared that individual filaments will strive to` contract to a greater degree than the stop of the movable holder would allow. This may cause rupture of the filament. It is therefore best to provide a spring between the stop and the fixed hook. This is attained by the above mentioned spiral windings of themovable lever 9 about the fixed hook 10. By this arrangement the movable lever 9 acts as a spring.

According to the modification shown in Figs. 9 to 11 inclusive, the immovable hook is formed with an eye 12 servin ,to limit the movement of the inner end .o the movable lever or member.

The movable parts of the anchoring devices described above, when made of heavy metal, may cause breakingl of the filaments because of 'accidental shocks during transportation. It is therefore advantageous to decrease as much as possible the weight of the holder, particularly its diameter, in order to attain greater safety against shocks during transportat'on. lIn this nnection, however, there exist condition that inthe region of contact of the ovable holder with the filament, sufficient me sof conducting away the heat must be rovi so that the temperature of the hol er may ain low during the burning of the lampls. \.Unless this is done the wires from whic the\hold ers have been formed may melt andthe lamps be thus destroyed. In accordance with this invention, the arrangement is' made that the movable holder 1s thickest at the loo forming the point of contact with the fi ament. For example, a movable' holder maybe made of two wires of different size fused together, as illustrated-by Fig. 12:, 1n whlch the support consists of a thin wire 9 and thick wire 13. .The thickening of the loop may also be brought about b ing 1n a reducing causing a conducting metallic powder toa here upon the same. For this purpose the vparticular metal of which the filament,is

composed, either entirely or `in part, is useful. This metal dis finely powdered and placed upon the Tint of contact in the form o'f a paste, and d into position by glowatmosphere. ySupports made 1n this way are illustrated in Figs. 6v to 11 inclusive.

What I claim as new and desire to secure by Letters Patent ofthe United States, is,-

1. A filament anchor having a pivotally supported movable part engaging with a filament loop and normally resting thereon to place the filament under tension proportional to the weight of the movable part.

2. A filament anchor comprising a hook rigidly mounted and amovable part engaging with the filament and spirally wound about said hook.

3. In an incandescent lamp, Ia filament anchoring device comprising two parts, one of which is fixed and the other of which hangs at an angle tothe fixed part and is movable to move the filament laterally when the filament contracts.

4. An anchor for a lamp filament consisting of two mounted, whlle the other is movable and by its weight tends' to hold the filament in position, and a spring which comes into action only after a predetermined contraction of the filament.

v 5. A filament anchor comprising a rigidly mounted hook and a movable member engaging with the filament and spirally wound -aboutsaid hook, said member having a spiing resistance to movement of said element outside of saidrange.

7. In an incandescent lamp, the combinationwith a lament loop, of a fixed support, and anchoring means for the filament pivoted on said support with its free end engaging and supported by said filament loop, the path of movement of said free end upon la contraction of said filament being an arc tending away froml said support.

8. In an incandescent lamp, the combination with a filament loop, of a fixed support, a` light, exible member for anchoring said filament pivoted on said support with its free end engaging' and supported by said filament loop, said member having a free pivotal movement over a certain range, land arts one of which is rigidly' stops for preventing the movement of said member beyond-said range except -by fiexure of said member.

9. An anchor for a refractory filament.

loop comprisi two parts, one fixed andthe other pivoted t ereon with its axis of movement transverse to the sides of the loop.

Vv10; In an incandescent lamp, the combination with a plurality of filament loops having their ends suitably supported, of in- In witness whereof, I have hereunto set dependent pivoted anchors for the several my hand this fourteenth day of February, 10 loopstsaid anchors having their free ends 1908.

envavinff and supported by the bights of the v 41 5 seierxl oops, the path of movement of the LUDVIG GLSLIL' free end of each of said anchors upon oon- Vitnesses:

traction of its lament loop being an are HANS GALEN,

tending away from the other anchors. GUSTAV MATTHIS. 

